An on-chip light source can deliver light to a photonic integrated circuit. An optical fiber can deliver the light from the photonic integrated circuit. It is desirable to reduce or eliminate light directed back from the optical fiber to the on-chip light source, which can cause noise or other instability in the light from the on-chip light source.
Corresponding reference characters indicate corresponding parts throughout the several views. Elements in the drawings are not necessarily drawn to scale. The configurations shown in the drawings are merely examples, and should not be construed as limiting the scope of the invention in any manner.